How to identify the quality earplug?1. Low rebound effectIf it is too flexible, anti-noise earplug swelling suppression the canal skin, can cause ear swelling, earache and other discomfort. Flexibility can not be too small to close contact with the external ear canal, noise effect will be reduced. So we must observe ear plug and play back the return time, the better the quality.2. ComplianceFlexibility directly affects the comfort level of wearing earplugs.3. Surface textureSome earplugs feel sticky, they will stick the ear canal skin when you worn on. We should avoid buying. The best way to identify is sticking two earplugs together closely then separating them. The separation time is the sooner the better.